Purpose: According to current knowledge, endothelin (ET)-1 plays an important role in the pathogenesis of systemic sclerosis (SSc). We assessed ET plasma levels in SSc patients according to the clinical presentation and the presence of complications such as pulmonary arterial hypertension (PAH).
Methods: Sixty-three consecutive patients with SSc were included. The control group included 17 healthy patients. ET plasma level was determined for all patients. Pulmonary function test and pulmonary high resolution computed tomography were performed in 44 patients and echocardiography in 51 patients, to screen for PAH, always confirmed by a right heart catheterization.
Results: ET plasmatic levels were higher in SSc patients than in healthy group subjects but the difference was not significant (3.72+/-1.13 vs 3.40+/-0.71 pmol/l, p=0.27). ET plasmatic levels were significantly higher in patients with PAH than in patients without PAH (4.28+/-0.65 vs 3.62+/-1.07 pmol/l, p=0.04) and in patients with anticentromere antibodies (3.96+/-1.11 vs 3.19+/-1.12 pmol/l, p=0.03). There was a positive linear correlation between ET plasmatic levels and systolic pulmonary arterial pressure (r=0.34, p=0.013). The best cut-off value for ET plasmatic level to discriminate patients affected by PAH was determined by ROC curve method: 4.1 pmol/l (sensibility 85.7%, specificity 66%).
Conclusion: ET plasmatic levels were higher in SSc patients affected by PAH and patients with anticentromere antibodies. There was a positive linear correlation between ET plasmatic levels and systolic pulmonary arterial pressure. Assessment of ET plasmatic levels for detection and monitoring of pulmonary hypertension during SSc is warranted in larger prospective studies.